There are a few ways users can be assigned to a device in Jamf School.
You can assign users to devices with two different types of .CSV uploads.
1.) You can use a placeholder CSV upload outlined in the knowledge base article here; https://support.jamfschool.com/hc/en-us/articles/115002304254-Placeholders
2.) You can make the association using a User .CSV Here you select "Import users from CSV" and upload your file. In that CSV you will see a field for serial number. If you add a device serial number there it will assign the user to that device.
You can also manually assign a device to a user by following these steps.
1.) Go to Devices in Jamf School and click on the device name in the device overview area.
2.) Click the "Edit Details" button in the upper right corner of the Device details screen.
3.) On the edit details page look for the "Current Owner" listing and from there you can either "Change" or if there is already a user assigned and you will also have the option to "Remove".
Remove will change the current owner to None and Change will bring you to a pop-up window of all the available users you have in Jamf School and allow you to assign one of them to the device.
4.) Once a user is assigned click the same button on the Edit Details page.
If you have any additional questions please open a support ticket in your Jamf School instance and we would be happy to assist you further.